/*
 *   Copyright 2021 zzh
 *
 *   Licensed under the Apache License, Version 2.0 (the "License");
 *   you may not use this file except in compliance with the License.
 *   You may obtain a copy of the License at
 *
 *       http://www.apache.org/licenses/LICENSE-2.0
 *
 *   Unless required by applicable law or agreed to in writing, software
 *   distributed under the License is distributed on an "AS IS" BASIS,
 *   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *   See the License for the specific language governing permissions and
 *   limitations under the License.
 *
 */

package com.aduib.boot.common.lang;

import java.util.Comparator;

import static java.lang.Integer.compare;

/**
 * @description: Prioritized
 * @author: zzh
 * @date: 2021/9/18 15:27
 */
public interface Prioritized extends Comparable<Prioritized> {

  /** The maximum priority */
  int MAX_PRIORITY = Integer.MIN_VALUE;
  /** The minimum priority */
  int MIN_PRIORITY = Integer.MAX_VALUE;
  /** Normal Priority */
  int NORMAL_PRIORITY = 0;
  /** The {@link Comparator} of {@link Prioritized} */
  Comparator<Object> COMPARATOR =
      (one, two) -> {
        boolean b1 = one instanceof Prioritized;
        boolean b2 = two instanceof Prioritized;
        if (b1 && !b2) { // one is Prioritized, two is not
          return -1;
        } else if (b2 && !b1) { // two is Prioritized, one is not
          return 1;
        } else if (b1 && b2) { //  one and two both are Prioritized
          return ((Prioritized) one).compareTo((Prioritized) two);
        } else { // no different
          return 0;
        }
      };

  /**
   * Get the priority
   *
   * @return the default is {@link #NORMAL_PRIORITY}
   */
  default int getPriority() {
    return NORMAL_PRIORITY;
  }

  @Override
  default int compareTo(Prioritized that) {
    return compare(this.getPriority(), that.getPriority());
  }
}
